The Aqua and Terra MODIS instruments helped scientists identify this large algal bloom off the eastern coast of Tasmania. Large blooms have not been detected in the Tasman Sea in the past, and scientists from CSIRO Marine Research, the largest marine research organization in Australia, believe this one resulted from the natural upwelling of nutrients along the island’s coast. The bloom is made up of coccolithophores, and is not believed to be harmful to the coastal ecosystem.

MODIS imagery, such as the image above, revealed just how large this bloom is. The bloom forms bright blue-green clouds in the water that stretch from Flinders Island in the north down the entire east coast of Tasmania. The color is caused by light reflecting off the chalky outer scales of millions of microscopic coccoliths. The effect is a cloud of bright blue or green water in satellite imagery. In addition to helping scientists identify algal blooms, the MODIS images “provide a valuable interpretation for researchers wanting to understand any impact this species may have in the coastal or offshore environments,” said Dr Susan Blackburn, a CSIRO researcher, in a recent press release. The above true-color MODIS image was acquired on October 20, 2004.